Chain saw



FIG. 1 is a right front side perspective view of the chain saw without a blade attached;

FIG. 2 is a left back side perspective view of the design shown in FIG. 1;

FIG. 3 is a back side view of the design shown in FIG. 1;

FIG. 4 is a right side view of the design shown in FIG. 1 with a blade attached;

FIG. 5 is a left side view of the design shown in FIG. 1;

FIG. 6 is a right side view of the design shown in FIG. 1; and,

FIG. 7 is a right back perspective view of the design shown in FIG. 1.

Any surfaces of the design not shown, including interior or bottom surfaces, form no part of the claimed invention. Moreover, the blade including the saw chain and bar of FIG. 4 also form no part of the claimed invention.

The broken lines shown in the drawings form no part of the claimed design. 

I claim the ornamental design for a chain saw, as shown and described. 